Key points are not available for this paper at this time.
The theory of ferromagnetic microwave amplification is presented in detail. All three possible types of operation using, respectively, two electromagnetic cavity modes, two sample modes, and one sample and one cavity mode, are discussed. One especially simple case, that of a sphere in the first type of operation is treated separately. Thereafter all three cases are discussed in terms of scaler and vector potentials. An appendix deals with the gain-band-width problem and gives an expression for the equivalent ``negative Q'' of the sample.
H. Suhl (1957) studied this question.